Borrowings - Tabular Information (Details) - USD ($)	Dec. 31, 2019	Jun. 30, 2019
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	$ 20,500,000	$ 44,200,000
FHLB fixed rate advance (2.45%, matures 7/1/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	7,500,000
FHLB fixed rate advance (2.43%, matures 7/2/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	15,000,000
FHLB fixed rate advance (2.45%, matures 7/3/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	5,000,000
FHLB fixed rate advance (2.43%, matures 7/3/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	8,000,000
FHLB fixed rate advance (2.649%, matures 7/23/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	2,500,000
FHLB fixed rate advance (2.649%, matures 7/24/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	3,100,000
FHLB fixed rate advance (2.647%, matures 7/25/19)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	0	3,100,000
FHLB fixed rate advance (1.72%, matures 1/2/20)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	4,000,000	0
FHLB fixed rate advance (1.72%, matures 1/3/20)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	7,500,000	0
FHLB fixed rate advance (1.72%, matures 1/6/20)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	3,000,000	0
FHLB fixed rate advance (1.74%, matures 1/7/20)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	1,000,000	0
FHLB fixed rate advance (1.74%, matures 1/7/20)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	500,000	0
FHLB fixed rate advance (1.72%, matures 1/8/20)
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank borrowings	$ 4,500,000	$ 0